1. Technical Field
The present invention relates to a safety restraint system for use in motor vehicles. In particular, the present invention is directed to an optical weight sensor for generating a signal indicative of the weight of a person or object seated or located in a vehicle seat.
2. Discussion
Safety restraint systems are used in motor vehicles for protecting the vehicle occupants during collisions. In addition to seat belts, many safety restraint systems now include a driver-side airbag mounted in the steering wheel and a passenger-side airbag mounted in the dashboard. Furthermore, recent attention has been directed to incorporation of other restraint devices such as, for example, side airbags, seat belt pretensioners, and energy management retractors into the safety restraint system. Many, if not all, of these restraint devices are activated by the vehicle's crash management system in response to detection of a vehicular collision exceeding a predetermined impact magnitude.
In order to optimize occupant protection during a collision, it is desirable to vary the deployment characteristics of the airbags and/or the operational characteristic of the other restraint devices based on various control parameters such as, for example, the severity of the crash, belt usage, and the position and size of the seat occupant. Thus, the vehicle's crash management system includes various sensors for detecting and/or measuring such control parameters. One particular control parameter that is useful for regulating the output characteristics of the restraint devices is the weight of the seat occupant. As such, a need exists to develop a weight sensing device for use in safety restraint systems.